In recent years, Equipment Engineering Systems (EES) have become popular to use in the manufacture of semiconductor apparatuses. The main purposes of the EES include fault detection (FD) and fault prediction (FP) (see NPL 1). Fault detection and fault prediction systems are organized hierarchically and may include fault detection and fault prediction at various levels such as a device control level, a module level, a sub-system, and an I/O device level. At the I/O device level, sensors or actuators are monitored for failure.
Typically, input data to actuators is transmitted as a long series of bits that represent sequences of control operations.
On the other hand, output data of sensors is a process measurement such as a temperature, a pressure, or a flow rate. It is not reasonable to store all of the output data, especially if sensor readings are taken every few milliseconds.
In light of this technical background, an EES compliant substrate processing device having an arithmetic operation module for obtaining a representative value and a verification module for checking has been proposed (see PTL 1). The representative value includes a maximum value, a minimum value, or an average value, and if fault detection and fault prediction can be realized by one of those values, the amount of data transmitted and the required amount of storage memory can be substantially reduced, and therefore those representative values are effective.